Absence of an association between water fluoridation and
Adopted by Expert Body, 14th June 2006
The Irish Expert Body on Fluorides and Health, as part of its terms of reference “To
advise the Minister and evaluate ongoing research - including new emerging issues - on
all aspects of fluoride, its delivery methods as an established health technology and as
required”, has reviewed and agrees with the following British Fluoridation Society’s
statement on the absence of an association between water fluoridation and thyroid
disorders. This statement was also reviewed and endorsed by the British Thyroid
British Fluoridation Society Statement (January 2006) on the absence of an
association between water fluoridation and thyroid disorders.
This statement has been reviewed and endorsed by the British Thyroid
The available medical and scientific evidence suggests an absence of an association
between water fluoridation and thyroid disorders.
Many major reviews of the relevant scientific literature around the world support this
conclusion. Of particular importance are:
an exhaustive review conducted in 1976 by an expert scientific committee of the
Royal College of Physicians of England;
a systematic review in 2000 by the NHS Centre for Reviews and Dissemination at
the University of York; and,
a 2002 review by an international group of experts for the International Programme
on Chemical Safety (IPCS), under the joint sponsorship of the World Health
Organisation (WHO), the United Nations Environment Programme (UNEP), and the
International Labour Organisation (ILO).
None has found any credible evidence of an association between water fluoridation and
any disorder of the thyroid.
Report of Royal College of Physicians
A scientific committee was established by the Royal College of Physicians to review
whether, and to what extent, water fluoridation benefited people’s teeth and whether
there were any harmful effects to general human health. As well as confirming that
water fluoridation reduces levels of tooth decay, the review also found that it was safe.
Specifically, the report concluded that “there is no evidence that fluoride is responsible
for any disorder of the thyroid”. It also confirmed that iodine deficiency was the root
cause of goitre, and that fluoride does not significantly influence the thyroid’s uptake of
The University of York Review
Published in 2000, the York Systematic review identified over three thousand
references in total. However, they found no scientific studies of an acceptable scientific
standard that would support suggestions of an association between water fluoridation
and thyroid disorders, including goitre, in the populations drinking fluoridated water.
When the Medical Research Council subsequently used the York report as a basis for
determining whether further research on any aspect of water fluoridation was needed, it
concluded on the basis of the evidence already available that new research on fluoride
and thyroid disorders should be regarded as a low priority.
Review by the International Programme on Chemical Safety (IPCS)
The IPCS review of fluoride was one of several published by the World Health
Organisation intended to “provide critical reviews on the effects on human health and
the environment of chemicals and of combinations of chemicals …” , and to “assist
national and international authorities in making risk assessments and subsequent risk
management decisions.” As such, it examined evidence on fluoride relevant to all
aspects of human health.
The review, which included 788 original studies from the worldwide scientific literature –
both published and unpublished - identified no evidence of an association between
fluoride and thyroid dysfunction in humans.
Experience in the UK’s most extensively fluoridated region
The conclusions of these authoritative reviews are mirrored by the experience of
specialist doctors diagnosing and treating thyroid disorders in hospitals in the West
Midlands, which has had fluoridation schemes in operation since the mid-1960s and
which is today the most extensively fluoridated region of the United Kingdom. Around
seven out of ten people in the West Midlands now drink water whose natural fluoride
content has been topped up to the optimum for dental health of one part of fluoride per
million parts of water.
Dr Andy Toogood, a consultant endocrinologist in the Department of Medicine at the
Queen Elizabeth Hospital in Birmingham, says that he and his colleagues have seen
nothing to suggest a rise in thyroid disorder cases resulting from water fluoridation.
Nor have public health officials who monitor trends in disease across the West Midlands
detected any impact on the health of local populations drinking fluoridated water - other
than a reduction in tooth decay levels which puts children living in the West Midlands
among the best in the country for dental health.
McDonagh, M., et al. (2000): A systematic review of public water fluoridation. York,
The University of York NHS Centre for Reviews and Dissemination. Report 18.
Medical Research Council (2002): Working Group Report: Water fluoridation and
health. London, MRC.
Royal College of Physicians (1976): Fluoride Teeth and Health. London, Pitman
International Programme on Chemical Safety (2002): Environmental Health
Criteria 227 FLUORIDES. Geneva, World Health Organisation.